Denoising and adaptive contrast enhancement in HDR image using local tone mapping

Tone mapping is the process in which the color of a HDR image are mapped into a normal image. This paper propose a local TM algorithm which compresses the luminance of high dynamic range (HDR) image using a simple luminance compression function and decomposes the compressed luminance of HDR image into multi-scale sub bands using the discrete wavelet transform. For noise reduction, the decomposed images are filtered using a MADN filter and soft-thresholding. And then, the dynamic ranges of the filtered sub bands are enhanced by considering local contrast using the modified luminance compression function. Finally, the color of the tone-mapped image is reproduced using an adaptive saturation control parameter. Also detect the impulse noise based on the absolute deviation to the median in each cluster. Computer simulation with noisy HDR images shows the effectiveness of the proposed local TM algorithm in terms of visual quality as well as the local contrast. It can be used in various displays with noise reduction and contrast enhancement.